The First Section:
Concerning the legal ruling of the prostration of forgetfulness.

The Second:
Identifying the points within the prayer where it is performed.

The Third:
Determining the category of acts involved and which specific actions require the prostration.

The Fourth:
Describing how the prostration of forgetfulness is to be carried out.

The Fifth:
Clarifying upon whom the prostration becomes obligatory.

The Sixth:
How a congregant should alert an absent-minded imam to his lapse.

The First Section
The jurists disagreed as to whether the prostration of forgetfulness is obligatory (farḍ) or recommended (sunnah). Al-Shāfiʿī held that it is a sunnah. Abū Ḥanīfah maintained that it is obligatory and, moreover, one of the conditions for the prayer’s validity. Mālik drew a distinction between lapses involving physical actions and those involving verbal elements, as well as between cases of omission and of addition. He said: “When the prostration of forgetfulness is occasioned by missing physical actions, it is obligatory and counts, in the well-known view, as a condition for the prayer’s soundness.” Another report from him states that the prostration made for omissions is obligatory, whereas that made for additions is merely recommended.

The reason for their divergence lies in how they understood the Prophet’s—peace and blessings be upon him—practice: did it indicate an obligation or a recommendation?

Abū Ḥanīfah took the Prophet’s actions in this matter to signify obligation, for that is, in his view, the default whenever the Prophet acts to clarify a duty, as in his statement, “Pray as you have seen me pray.”

Al-Shāfiʿī regarded those actions as indicating recommendation and, by way of analogy, removed them from the default of obligation. Since, according to the majority, this prostration does not stand in place of a compulsory element but rather substitutes for something recommended, he reasoned that a replacement for what is not obligatory cannot itself be obligatory.

As for Mālik, he considered the physical actions of prayer more emphatic than its verbal components—because the obligatory actions outnumber the obligatory utterances. Hence he deemed such actions weightier, even though the prostration of forgetfulness only substitutes for something that is itself non-obligatory. His further distinction between prostrations for omission and for addition (in the second narration) reflects his view that the first was legislated as a substitute for what has fallen away from the prayer’s parts, whereas the second functions more like an act of seeking forgiveness than as a true substitute.